Can someone give me a written soloution to this question please?
Let ABC be a spherical triangle on the surface of the Earth. Suppose that
AngleA = 80, AngleB = 70, AngleC = 60. What is the area of the spherical triangle
ABC in square kilometres? (Assume that the Earth is an exact sphere of
radius 6371 km. Your answer must be correct up to 1,000,000 km2.)